Chemical Composition (%)
| Zn | Balance (matrix) |
|---|---|
| Al | High addition, raises strength and hardness markedly |
| Cu | Raises strength, hardness and dimensional stability |
| Mg | Refines structure, improves dimensional stability |
Mechanical & Physical Properties
| Friction coefficient | 0.08-0.12 (copper alloys about 0.15-0.20) |
|---|---|
| Wear loss | About 1/4 of copper alloys |
| Service life | About 2-3 times tin bronze |
| Density | About 2/3 of copper |
Typical Applications
Grade Overview
ZA303 is a high-aluminium zinc-based bearing alloy developed as a lower-cost replacement for tin bronze in slow-speed, high-load sliding applications. Against steel its friction coefficient is about 0.08-0.12, compared with roughly 0.15-0.20 for copper alloys; wear loss is about one quarter of copper alloys and service life in comparable bushings is typically 2-3 times that of tin bronze. Density is about two thirds of copper, so the same part weighs less and costs less in material.
Selecting ZA303
Choose ZA303 for bushings, bearing shells, liner plates, lead-screw nuts and slide plates running at slow to moderate speed under steady load, especially where tin bronze is being replaced to cut cost or weight. It is not intended for high-speed continuous duty or for parts that must carry shock at elevated temperature; confirm the duty with the drawing and the lubrication method.
Working with ZA303
ZA303 casts and machines on conventional foundry equipment. Melt control matters: aluminium and magnesium levels govern strength and dimensional stability, and the melt must be kept clean and degassed to avoid porosity. Machining is fast and produces continuous chips; use sharp tooling and avoid overheating the surface. Bushings are usually cast to near-net shape and finish-machined.
Frequently asked questions about ZA303
Is ZA303 a standard grade?
It is a company grade rather than a GB or ASTM designation. Properties are controlled by the supplier's specification and should be confirmed on the mill certificate.
Can ZA303 replace tin bronze directly?
In slow-speed, high-load bushings it often can, with lower weight and cost. Check the load, speed and lubrication of the specific application first; high-speed or shock-loaded duty is not a direct substitution.
Does ZA303 contain copper?
Yes. Copper is added to raise strength, hardness and dimensional stability, together with aluminium and a small magnesium addition.
Data compiled from current standards; for selection reference only. Ordering is subject to the standard and the mill certificate. Data source: Shenyang Yuheng Metal Manufacturing Co., Ltd. — yuhengmetal.com.
Related zinc alloy grades
ZCuSn10P1 · ZCuAl9Fe4Ni4Mn2 · ZZnAl27Cu2Mg | All 52 grades in the library